1. Field of the Invention
The present invention relates to a method of and an apparatus for manufacturing a woven slide fastener stringer having a row of continuous filamentary coupling elements woven integrally into a stringer tape, and an article produced by such method and apparatus. More particularly, the invention is directed to the provision of a woven slide fastener stringer having such a row of coupling elements which are disposed so as to be concealed or masked from external view when the slide fastener is closed.
2. Prior Art
Various methods and apparatus for manufacturing woven slide fastener stringers have been proposed as disclosed for example in Japanese Patent Publication No. 59-51815 or Japanese Patent Publication No. 63-37642 wherein an element-forming filamentary material is woven into one longitudinal edge of a stringer tape simultaneously as the latter is woven. However, such prior art methods and apparatus are not capable of forming a woven slide fastener stringer of a concealed type with a row of coupling elements arranged to be concealed from view in a manner contemplated by the invention.
A concealed type of woven slide fastener is known typically from German Patent No. 1,216,594 wherein there is provided a stringer having a row of helically coiled coupling elements and a relatively thick longitudinal stiffening cord running between upper and lower leg portions of the elements, the leg portions being bound in place by warp and weft threads tensioned against the cord. This prior art stringer is literally thick or bulky along its longitudinal edge to which the coupling elements are secured and hence the coupling elements when woven present a relatively high profile leading to reduced flexibility.
Another concealed woven slide fastener is disclosed in Japanese Patent Publication No. 46-7018, which however has a drawback in that coupling elements in a continuous row are woven in the absence of linearly extending warp threads so that an element pitch or an element-to-element spacing becomes irregular or disarrayed, leading to inadvertant disengagement of the coupling elements on one stringer from those on the opposite mating stringer.